Agriculture

  2009 APR 30 - (VerticalNews.com) -- According to recent research published in the Journal of Arid Environments, "Biomass was measured at 48 undefoliated grassland sites on a 1900-km transect in Inner Mongolia. Above-ground biomass was separated into leaf, stern, flower and fruit, and dead matter, and into the five dominant species at each site."

  "Below-ground biomass was measured to a depth of 30 cm and separated into 10-cm layers. Changes of these biomass components and their ratios were examined in relation to gradients of temperature and precipitation, and to the classification of the sites into five grassland types. Total biomass decreased markedly as site mean annual temperature increased and to a smaller extent as mean annual precipitation decreased. Averaged over all sites 92% of biomass was below ground. The proportion of below-ground biomass increased as temperature decreased, and was least and distributed more deeply in desert grassland. As aridity of the grassland types increased, the proportion of biomass in the first dominant species and in stem relative to leaf tissue increased," wrote J.W. Fan and colleagues, China Agricultural University ...read more

  2008 MAY 5 - (VerticalNews.com) -- "In order to investigate the productivity of hilly grassland of the Xilin River Basin as affected by slope aspect (North versus South), aboveground green biomass (AGB) and species composition were studied at four hill sites in 2005. Additionally, a detailed investigation combining vegetation parameters, physical and chemical soil characteristics was carried out at different slope positions (base, middle, and top) of north and south slope aspect on one of the hills in 2004 and 2005," researchers in Beijing, People's Republic of China report ...read more

  2008 MAR 17 - (VerticalNews.com) -- "Saffron (Crocus sativus L.) is an important prennial crop planted in Iran. The growing period of saffron is mostly winter and spring, which makes it a popular crop in areas with limited water supply," scientists writing in the Journal of Arid Environments report.

  "Crop coefficients, K-c (the ratio of crop potential evapotranspiration (ETcp) to reference crop evapotranspiration (ETo) of saffron are needed to calculate water requirements. ETo was estimated by the FAO Penman procedure. The values of ETcp and ETo were 486 and 991 mm for the first year (1998-1999), and 670 and 975 mm for the second year (1999-2000), respectively. Higher ETcp for the second year was due to the higher number of corms per unit area. The values of K-c varied through the growing season from 0.22-0.24 to 0.94-1.05, and 0.68-0.78 at the beginning, middle and end of the crop's cycle for both years. The pan coefficient varied from 0.23 to 1.10 for the first growing season and from 0.32 to 1.12 for the second growing season," wrote A. Azizizohan and colleagues, Shiraz University ...read more

  2008 MAR 17 - (VerticalNews.com) -- According to recent research from the United States, "Semi-arid ecosystems cover tens of millions of hectares in the Intermountain West of the United States, and most have altered plant communities due to land use, especially livestock grazing. Thus, relatively unaltered ''reference'' plant community information is needed to guide restoration."

  "Plant communities were sampled over a large (similar to 600 000 ha) semi-and landscape in western Colorado, within pinon-juniper woodlands, sagebrush shrublands, and grasslands, and over conditions ranging from relict areas without livestock grazing to heavily utilized areas. Ordination was used to group samples into ranked categories of ecological condition within 18 communities, and means-tests and other techniques were used to identify ecological differences among ranks across vegetation types. With few exceptions, grass and forb cover, biological soil crust cover, and species diversity declined concomitant with ranks representing increasingly degraded conditions, while non-native species cover was variable among ranks. Landscape-level species abundance patterns also differed significantly among ranks, with herbaceous species generally exhibiting less constancy and cover within degraded samples compared to samples of reference quality," wrote D.J. Shinneman and colleagues, Department of Agriculture ...read more